Streptococcus pyogenes bloodstream infections in an Italian hospital: A ten-year genomic picture

• DOI: 10.1016/j.jiph.2025.102701
• Publication Date: 2025-02-12T00:09:57Z
• Authors: Marta Corbella; Cristina Merla; Angela Kuka; Irene Mileto; Greta Petazzoni; Chiara Rebuffa; Vincenzo Brunco; Stefano Gaiarsa; Fausto Baldanti; Patrizia Cambieri
• Keywords: Streptococcus Pyogenes; Bloodstream infection

During 2022 and 2023, a large upsurge of cases Group A Streptococcus (GAS) infection has struck many countries worldwide. This epidemic event was caused by diminished level immunity after COVID-19 social restrictions fostered mainly the emm1 genotype bacterium. We characterized genomes GAS isolates that bloodstream infections in last ten years 900-bed hospital Northern Italy. obtained short-read genomes, which we used for emm typing to analyze antimicrobial resistance virulence gene content. Moreover, contextualized an epidemiological point view using both ortholog-based SNP-based phylogeny. In years, registered two upsurges study hospital: one 2023 (in line with global situation), 2016 (local, but observed also another recent Italian study). The genomic analysis showed circulation multiple types, emm1, emm12, emm4 events. Notably, peak M1Global genotypes, contrast rise M1UK UK pre-pandemic years. Phylogeny presence monophyla local strains. Despite our being from blood-culture isolates, did not observe any increased or genes. Our results further confirm role as most prevalent However, unveiled central event, described hospital. Finally, suggest locally persistent Among these, underlined multi-drug resistant strain emm92.